Epoxy asphalt for long lived pavement on long span bridges

1,552 views
1,478 views

Published on

Epoxy Asphalt is an extremely durable pavement typically used on long span bridges with orthrotropic steel decks. It is also used for very durable overlays (as thin as ¾ inch or 19 mm) on concrete decks.

Epoxy Asphalt’s first major installation and longest service life is on the San Mateo Bridge in Northern California, where it is still in use after 46 years. Its heaviest use is on the Bay Bridge between Oakland and San Francisco where traffic counts are 280,000 daily vehicles over 10 lanes. The Bay Bridge overlay is 19 mm and has lasted 37 years.

Epoxy Asphalt is a thermoset polymer unlike regular and polymer modified asphalt binders, the latter of which are thermoplastics. It does not melt, does not rut or shove and is many times stronger than normal asphalts. It offers 3-4 orders of magnitude improved fatigue resistance (won't crack under repeated flexing).

Epoxy Asphalt is placed with standard asphalt paving equipment and plants. Epoxy Asphalt is manufactured by ChemCo Systems in Redwood City CA (www.chemcosystems.com).

Published in: Business, Technology
1 Comment
3 Likes
Statistics
Notes
No Downloads
Views
Total views
1,552
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
64
Comments
1
Likes
3
Embeds 0
No embeds

No notes for slide

Epoxy asphalt for long lived pavement on long span bridges

  1. 1. Epoxy Asphalt Durable pavement for Steel Decks ChemCo Systems
  2. 2. Epoxy Asphalt History  late 1950s Shell Oil develops jet fuel and hydraulic oil resistant paving for airport taxiways.  1966 Caltrans uses Epoxy Asphalt on San Mateo- Hayward Bridge (in use—46 yrs. of service).  1976 Bay Bridge ¾” (19mm) overlay on lightweight concrete (in use—36 yrs. of service, 280,000 vehicles/day).  1986 Golden Gate Bridge redecked (in use).  2000 2nd Nanjing Br. (first Asia project). --5th generation product designed for high heat and wheel loads  2013 6th generation product ChemCo Systems
  3. 3. Epoxy AsphaltApplications  Orthotropic steel decks • New construction • Replacement paving • Re-decking  Overlays  Temporary chip seals  High (heavy weight) traffic, strategic roads with long life requirement  Fuel and chemical resistant paving Lionsgate Br ChemCo Systems
  4. 4. Epoxy AsphaltReplacement paving  Uses standard paving equipmt  Can close only one lane  Reopened in 2 hrs  Day or night placement ChemCo Systems
  5. 5. Epoxy AsphaltRedeckingDeck sections can be chip sealed at fabrication plant ChemCo Systems
  6. 6. Epoxy AsphaltEA Chemistry  Epoxy cross-linked polymer continuous phase, asphalt discontinuous phase  2 component binder and 2 component bond coat • Part A Resin • Part B Asphalts and cross-linkers  Ambient temperature cure mechanism  Cured polymer is thermoset (won’t melt) ChemCo Systems
  7. 7. Epoxy AsphaltProperties  Extremely high fatigue resistance  Ultra high strength bond coat • Protects against delamination • Ensures composite action with steel  Thermoset • Will not melt Element meshing  Higher modulus than other flexible pavements • Reduces deck deflection “Epoxy Asphalt has a fatigue life of 2 to 3 orders of magnitude greater than the PG76-22 I-5 mix…”. --Rutgers University study ChemCo Systems
  8. 8. Epoxy AsphaltProperties  Does not oxidize • No embrittlement upon aging Low voids (typically ~2 %) • Water impermeable • No chloride ion High Temperature bond performance FHWA OECD Long Lived Pavement Study penetration Turner Fairbanks Highway Research Center ChemCo Systems
  9. 9. Epoxy AsphaltFundamental difference HMA Asphalt, SMA, Gussasphalt, PMA are thermoplastics: will melt Epoxy Asphalt is thermoset: will not melt “Epoxy Asphalt concrete has shown excellent performance including anti-cracking feature under low temperature, stability under high temperatures and oil-corrosion resistance.…” --W. Wang, Chang’an University ChemCo Systems
  10. 10. Epoxy Asphalt Advantages  Low permeability prevents deck corrosion  Fatigue resistance minimizes cracks  4+ times more stability than standard AC  Handles truck wheel overloads --Rutgers Univ. (to 120 MT in Asia) ChemCo Systems
  11. 11. Epoxy Asphalt Advantages  No rutting or shoving  Roadway can open in 2 hrs  Use standard AC paving equipment • Very high bond strength  Won’t delaminate “The superior oxidation resistance of the epoxy asphalt material was even more obvious in the Cantabro tests…” --Transit New Zealand—OECD report ChemCo Systems
  12. 12. Epoxy Asphalt Typical new construction detail ChemCo Systems
  13. 13. Epoxy Asphalt EA Specifications  Dense graded mix, ½” (12mm) minus • Basalt rock for skid resistance and long wear • Typical compaction to 2%  Low temperature paving (110- 121ºC) • Time/temp monitoring is critical QC element • Similar temps to warm mix  Lab simulation (fatigue testing) advised for unique decks ChemCo Systems
  14. 14. Epoxy AsphaltEA Equipment: metering for quality Bond coat machine Meter/mix machine (at batch plant) ChemCo Systems
  15. 15. Epoxy Asphalt O-T Deck Pavement Stress from wheel load deflection TENSION Longitudinal stiffener ChemCo Systems
  16. 16. Epoxy Asphalt Fatigue testing evaluate pavement design on project specific deck  Keys • Realistic paving composite specimens • Good tests take time • Research performance of local materials (aggregates) • Use environmental chamber to control extreme temps ChemCo Systems
  17. 17. Epoxy Asphalt Stress simulation: Epoxy Asphalt fatigue test specimen ●12 mm plate ● 300 mm stiffener spacing, ● center load of 5kN ChemCo Systems
  18. 18. Epoxy AsphaltComparison: EA vs. polymer modified ACor SMA Properties Condition Epoxy Asphalt Polymer AC High temperatures Will not melt Melts Permeability None measurable Changes with age a. Will not oxidize a. Oxidizes b. Flexibility constant b. Flexibility No age related declines performance losses Delamination potential Very low High Consistent composite behavior Fuel resistance High Low—will soften and dissolve binder Rutting, shoving Stable Unstable under high temps and loads ChemCo Systems
  19. 19. Epoxy Asphalt Chinese standard deck detail Fatigue test specimen with 3 pt. dynamic load on 300 mm center 300 mm stiffener 50-55 mm EA paving spacing Locus of highest stress is 12 mm deck plate (prior over stiffeners, particularly to 1999) in truck lanes 14-16 mm deck plate Dynamic fatigue test is (after 1999) good predictor ChemCo Systems
  20. 20. Epoxy Asphalt Asian conditions  High deck pavement temps • To 90 °C  Extreme temperature cycle between winter and summer  Construction QC varies widely  Standardized deck design in mainland ChemCo Systems
  21. 21. Epoxy Asphalt Asian conditions Consistent very high truck wheel overloads • To 120 MT on 18 wheelers • SMA and gussasphalt sometimes fail as quickly as 2-3 yrs. SuTong Br. ChemCo Systems
  22. 22. Epoxy Asphalt EA: Disadvantages  Time and temperature controls critical • QC Controls lead to higher quality and uniformity • Paving plant needs to be within 50 minute drive  Too complicated • Over 35 bridges in Asia in past 10 yrs successfully completed – including 1st suspension bridge in Viet Nam • ChemCo provides on-site advisors • Use test section in convenient location to train local paving crews before deck placement  Costs more • Cost difference dwarfed by frequent closures and repaving Thuan Phuoc Bridge DaNang, Viet Nam ChemCo Systems
  23. 23. Epoxy AsphaltN. America news Fremont, Portland • Repaved in July 2011 (after 39 years of service) San Francisco-Oakland Bay 2013 • Single anchored suspension (new East Span) • Opens Sept 2013 MacDonald, Nova Scotia ~2016 • Redeck similar to Lionsgate (Vancouver BC) ChemCo Systems
  24. 24. Epoxy AsphaltFuture Reduce pavement weight  Improve fatigue Local manufacturing performance in most OECD-ECMT Joint challenging Transport Research applications on long life • Decks with pavements extremely high wheel • (U.S., U.K., France, overloads Germany, Denmark, New Zealand, • Decks with thin Australia) plates (12 mm) • Open graded • Hottest tropical performance benefits demonstrated environments ChemCo Systems
  25. 25. Epoxy AsphaltConclusions Design, test and  Asian lessons learned confirm for wear course • Over design success surfacing when Epoxy Asphalt, a realistic data not thermoset material, available performs on challenging • Be flexible to adopt decks local improvements Epoxy Asphalt offers life cycle cost benefits ChemCo Systems
  26. 26. Epoxy Asphalt Thanks for your interest! ChemCo Systems

×